769-60-8Relevant academic research and scientific papers
A Novel Synthesis of β-Trichlorostannyl Ketones from Siloxycyclopropanes and Their Facile Dehydrostannation Affording 2-Methylene Ketones
Ryu, Ilhyong,Murai, Shinji,Sonoda, Noboru
, p. 2389 - 2391 (1986)
Site-selective ring cleavage of siloxycyclopropanes 2 with stannic chloride (SnCl4) leads to good yields of β-trichlorostannyl ketones 3.Subsequent treatment of 3 with dimethyl sulfoxide (Me2SO) in chloroform at 60 deg C results in the facile dehydrostannation to give good yields of 2-methylene ketones 4.
Merging Halogen-Atom Transfer (XAT) and Cobalt Catalysis to Override E2-Selectivity in the Elimination of Alkyl Halides: A Mild Route towardcontra-Thermodynamic Olefins
Zhao, Huaibo,McMillan, Alastair J.,Constantin, Timothée,Mykura, Rory C.,Juliá, Fabio,Leonori, Daniele
supporting information, p. 14806 - 14813 (2021/09/18)
We report here a mechanistically distinct tactic to carry E2-type eliminations on alkyl halides. This strategy exploits the interplay of α-aminoalkyl radical-mediated halogen-atom transfer (XAT) with desaturative cobalt catalysis. The methodology is high-yielding, tolerates many functionalities, and was used to access industrially relevant materials. In contrast to thermal E2 eliminations where unsymmetrical substrates give regioisomeric mixtures, this approach enables, by fine-tuning of the electronic and steric properties of the cobalt catalyst, to obtain high olefin positional selectivity. This unprecedented mechanistic feature has allowed access tocontra-thermodynamic olefins, elusive by E2 eliminations.
Nickel-Catalyzed C(sp3)-H Functionalization of Benzyl Nitriles: Direct Michael Addition to Terminal Vinyl Ketones
Zhang, Ninghui,Zhang, Chunli,Hu, Xiaoping,Xie, Xin,Liu, Yuanhong
supporting information, p. 6004 - 6009 (2021/07/31)
An efficient nickel(0)-catalyzed addition of benzyl nitriles to terminal vinyl ketones via C(sp3)-H functionalization has been developed. The reaction provides a novel and efficient protocol for the synthesis of α-functionalized benzyl nitriles with a wide range of structural diversity under mild reaction conditions while obviating the use of a strong base. The work might be potentially useful toward the development of an enantioselective variant using chiral nitrogen ligands.
Chemoselective reduction of ?,￠-unsaturated carbonyl and carboxylic compounds by hydrogen iodide
Matsumoto, Shoji,Marumoto, Hayato,Akazome, Motohiro,Otani, Yasuhiko,Kaiho, Tatsuo
, p. 590 - 599 (2021/03/29)
The selective reduction of ?,￠-unsaturated carbonyl compounds was achieved to produce saturated carbonyl compounds with aqueous HI solution. The introduction of an aryl group at an ? or ￠ position efficiently facilitated the reduction with good yield. The reaction was applicable to compounds bearing carboxylic acids and halogen atoms. Through the investigation of the reaction mechanism, it was found that Michael-type addition of iodide occurred to produce ￠-iodo compounds followed by the reduction of C-I bond via anionic and radical paths.
Asymmetric Catalytic Epoxidation of Terminal Enones for the Synthesis of Triazole Antifungal Agents
Feng, Xiaoming,He, Qianwen,Liu, Xiaohua,Zhang, Dong,Zhang, Fengcai
supporting information, p. 6961 - 6966 (2021/09/11)
An enantioselective epoxidation of α-substituted vinyl ketones was realized to construct the key epoxide intermediates for the synthesis of various triazole antifungal agents. The reaction proceeded efficiently in high yields with good enantioselectivities by employing a chiral N,N′-dioxide/ScIII complex as the chiral catalyst and 35% aq. H2O2 as the oxidant. It enabled the facile transformation for optically active isavuconazole, efinaconazole, and other potential antifungal agents.
Palladium-Catalyzed Synthesis of α-Methyl Ketones from Allylic Alcohols and Methanol
Biswal, Priyabrata,Chandrasekhar, Vadapalli,Meher, Sushanta Kumar,Samser, Shaikh,Venkatasubbaiah, Krishnan
supporting information, (2021/11/01)
One-pot synthesis of α-methyl ketones starting from 1,3-diaryl propenols or 1-aryl propenols and methanol as a C1 source is demonstrated. This one-pot isomerization-methylation is catalyzed by commercially available Pd(OAc)2 with H2O as the only by-product. Mechanistic studies and deuterium labelling experiments indicate the involvement of isomerization of allyl alcohol followed by methylation through a hydrogen-borrowing pathway in these isomerization-methylation reactions.
Palladium-Mediated Tandem Isomerization-Methylenation of Allyl Alcohols: One-Pot Synthesis of 1,5-Diketones
Samser, Shaikh,Mohapatra, Omkar,Biswal, Priyabrata,Venkatasubbaiah, Krishnan
, p. 13744 - 13753 (2021/10/12)
A novel methodology for the synthesis of 1,5-diketones through a one-pot isomerization-methylenation of a variety of allylic alcohols has been established for the first time. This methodology utilizes commercially available palladium acetate and easily accessible BINOL phosphoric acid. Both isomerization of allylic alcohol and oxidation of methanol occurred through a single catalyst. The practical utility of the methodology has been shown by synthesizing substituted pyridines via sequential addition. Mechanistic investigation reveals the isomerization of allylic alcohols to the corresponding ketone, which ultimately undergoes methylenation, leading to 1,5-diketones, having H2 and H2O as the only byproduct.
Cobalt(II)porphyrin-Mediated Selective Synthesis of 1,5-Diketones via an Interrupted-Borrowing Hydrogen Strategy Using Methanol as a C1 Source
Biswal, Priyabrata,Samser, Shaikh,Nayak, Prakash,Chandrasekhar, Vadapalli,Venkatasubbaiah, Krishnan
, p. 6744 - 6754 (2021/05/29)
A novel cobalt(II)porphyrin-mediated acceptorless dehydrogenation of methanol is reported for the first time. This methodology has been applied for the coupling of a variety of ketones with methanol to produce 1,5-diketones along with H2 and H2O as the environment friendly byproducts. This paradigm was also demonstrated for a one-pot synthesis of substituted pyridines using a sequential addition protocol where the 1,5-diketones were generated in situ. From many experiments including those involving deuterium labeling, it is proposed that protonated cobalt(II)porphyrin methoxide complex acts as an intermediate to generate formaldehyde along with a metal hydride.
β-Borylation of conjugated carbonyl compounds with silylborane or bis(pinacolato)diboron catalyzed by Au nanoparticles
Fragkiadakis, Michael,Kidonakis, Marios,Stratakis, Manolis
supporting information, p. 8921 - 8927 (2020/11/23)
Conjugated aldehydes and ketones undergo reaction with Me2PhSiBpin (pin: pinacolato) catalyzed by Au nanoparticles supported on TiO2 forming exclusively the β-borylation products, via the intermediate formation of the labile silaboration adducts. This chemoselectivity pathway is complementary to the so far known analogous reaction catalyzed by other metals, where β-silylation occurs instead. β-Borylation also occurs with pinBBpin under identical reaction conditions in a variety of conjugated carbonyl compounds, including esters and amides which are unreactive in their attempted Au-catalyzed silaboration. This journal is
Br?nsted Base-Catalyzed Transformation of α,β-Epoxyketones Utilizing [1,2]-Phospha-Brook Rearrangement for the Synthesis of Allylic Alcohols Having a Tetrasubstituted Alkene Moiety
Kondoh, Azusa,Tasato, Naoko,Aoki, Takuma,Terada, Masahiro
, p. 5170 - 5175 (2020/07/04)
A stereoselective transformation of α,β-epoxyketones into alkenylphosphates having a hydroxymethyl group on the β-carbon was established by utilizing the [1,2]-phospha-Brook rearrangement under Br?nsted base catalysis. The reaction involves the catalytic generation of an α-oxygenated carbanion located at the α-position of an epoxide moiety through the [1,2]-phospha-Brook rearrangement and the following epoxide opening. Further transformation of the alkenylphosphates by the palladium-catalyzed cross-coupling reaction with Grignard reagents provided allylic alcohols having a stereodefined all-carbon tetrasubstituted alkene moiety.
